diff --git a/photon/libc/include/time.h b/photon/libc/include/time.h
index 53d67fc..4a0976e 100644
--- a/photon/libc/include/time.h
+++ b/photon/libc/include/time.h
@@ -30,6 +30,8 @@ struct tm {
 extern clock_t clock(void);
 extern time_t time(time_t *p);
 
+extern int nanosleep(const struct timespec *req, struct timespec *rem);
+
 extern struct tm *gmtime(const time_t *timer);
 extern struct tm *localtime(const time_t *timer);
 extern time_t mktime(struct tm *timeptr);
diff --git a/photon/libc/sys/horizon/time.c b/photon/libc/sys/horizon/time.c
index 6705b2e..6aa78c6 100644
--- a/photon/libc/sys/horizon/time.c
+++ b/photon/libc/sys/horizon/time.c
@@ -1,7 +1,9 @@
 #include <magenta/types.h>
+#include <magenta/misc.h>
 #include <magenta/errors.h>
 #include <magenta/clock.h>
 #include <time.h>
+#include <errno.h>
 
 clock_t __sys_clock(void)
 {
@@ -19,6 +21,17 @@ time_t __sys_time(void)
     return v.sec;
 }
 
+int nanosleep(const struct timespec *req, struct timespec *rem)
+{
+    if (!req) {
+        __set_errno(EFAULT);
+        return -1;
+    }
+
+    mx_nanosleep(mx_deadline_after(MX_SEC(req->tv_sec) + MX_NSEC(req->tv_nsec)));
+    return 0;
+}
+
 int __sys_clock_getres(clockid_t clk_id, struct timespec *res)
 {
     mx_time_val_t v;